I wonder if it utterly fucked his speech centers? If it was damaged, then we have three possible futures:
1. He has Broca's Aphasia. If that's the case then he can understand people... well as best as mushbrain can already understand people I should say. Thing is though he won't really be able to say what he exactly wants. If this is the case then he can probably only say things like "Jack. Birria. Lookadat beautiful. Gud." No particles, and just the bare statements, with a lot of verbal pausing.
2. He has Wernicke's Aphasia. This is funny, since he will ramble as much as he does now, but it's all gonna be horseshit that makes no sense. He also won't really understand anything he wants. If he has this fate, expect him to say shit like "On the go for Jack tacos. Have cook for birria meat so gud so that can." Fluent, but it's gonna be rambling horseshit at best. And that's with some therapy.
3. General Aphasia. The worst of both worlds for him and a shame we probably wouldn't get to actually see him gurgle and babble out random grunting words. He'd probably only be able to say shit like "Miitsogud Jack gud want gud meat meat so gud Jack go go meat". Literal fucking garbage.
I actually hope he's so committed to eating out and cheating the IRS in the process he forces Tammy to continue to do Fat on the Go for the writeoffs, just to see a nightmare like that.